A Novel Approach to Reduce Line Harmonic Current for a Three-phase Diode Rectifier-fed Electrolytic Capacitor-less Inverter

This paper describes a three-phase high power factor rectifier for an electrolytic capacitor-less inverter based on the current injection scheme. The rectifier injects the machine side zero sequence current into the grid side through three bi-directional switches. This paper also introduces the modified circuit topology which is suitable for an electrolytic capacitor-less inverter. A bulky dc or ac reactor can be removed due to small capacitance of the proposed circuit topology. The principle of current injection and a proper current control method based on a feed-forward control concept have been described in this paper. The validity of the proposed circuit topology has been confirmed by simulation and experimental results.